1. Field of the Invention
The present invention relates to signal processing techniques. More particularly, the present invention relates to methods for processing audio signals.
2. Description of the Related Art
Existing matrixed surround decoders such as Dolby Prologic or DTS Neo:6 are designed to “upmix” 2-channel audio recordings for playback over multichannel loudspeaker systems. These decoders assume that sounds are directionally encoded in the 2-channel signal by panning laws that introduce inter-channel amplitude and phase differences specifying any desired position on a horizontal circle surrounding the listener's position. Known limitations of these decoders include (1) their inability to discriminate and accurately position concurrent sounds panned at different positions in space, (2) their inability to discriminate and accurately reproduce ambient or spatially diffuse sounds, (3) their limitation to 2-D horizontal spatialization, (4) their inherent restriction to conventional multichannel audio rendering techniques (pairwise amplitude panning) and standard multichannel loudspeaker layouts (5.1, 7.1). It is desired to overcome these limitations.
What is desired is an improved matrix decoder.